The discovery of the remarkable antibiotic properties of penicillin stimulated great interest in this field which has resulted in the finding of many other valuable antibiotic substances such as: streptomycin, bacitracin, chlortetracycline, oxytetracycline and the like. In general, the activity of such antibiotics is confined either to the gram-positive or to the gram-negative bacterial pathogens. Even in those cases where a broader spectrum of antibacterial activity obtains, certain pathogenic species remain either intrinsically insensitive or have acquired resistance over the course of intensive use of the existing antibiotics in the treatment of various diseases.
Accordingly, the deficiencies of the known antibiotics have stimulated further research to find other antibiotics which will be active against a wider range of pathogens as well as resistant strains of particular microorganisms.